1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a data driving apparatus for a liquid crystal display device for reducing a heating value of a driver integrated circuit (IC).
2. Discussion of the Related Art
Representative examples of a flat display apparatus for displaying an image using digital data include a liquid crystal display (LCD) device using liquid crystal, a plasma display panel (PDP) using discharge of inert gas, a organic light emitting diode (OLED) display device using an OLED, and the like. Among these, the LCD device has been widely used in various application fields such as in a television (TV), a monitor, a notebook computer, and a portable phone.
An LCD device displays an image through a pixel matrix using the electrical and optical properties of liquid crystal having anisotropic properties with respect to refractive index, dielectric constant, and the like. Each pixel of the LCD device implements a gray level by adjusting optical transmittance with respect to a polarization plate using variation in liquid crystal arrangement direction according to a data signal. The LCD device includes a liquid crystal panel for displaying an image through the pixel matrix, a gate driver and data driver for driving the liquid crystal panel, a backlight unit for irradiating light to the liquid crystal panel, and a backlight driver for driving the backlight unit.
A high resolution and large size LCD device has been developed. Accordingly, a driving frequency and load amount of a drive integrated circuit (IC) for supplying a data voltage to a liquid crystal panel needs to be increased and a positive data voltage and a negative data voltage need to be swing for inversion driving of the liquid crystal panel, and thus, a heating value of the drive IC has been increased. When a temperature of the drive IC increases, reliability of the drive IC is degraded and a safety hazard such as ignition is caused. Accordingly, there is a need to lower the temperature of the drive IC.
In general, an output buffer for buffering a data signal from a digital-analog converter (DAC) to a drive IC and outputting the data signal to a data line is a most power-consumed component, the output buffer acts as a main heating source of the drive IC. Accordingly, there is a need for a method of reduce output current of the output buffer in order to reduce a heating value of the drive IC.